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questions about Kortek chassis

Posted: October 11th, 2008, 11:20 am
by ckong
I have an old neo geo cab with a 19" monitor in it and with a Kortek KTN 20 chassis:

Image

I have a few questions about it:

A. what are the two black switches for (Marked 'A' in the picture)? The left is marked 'HS' and the right is marked 'VS'. They both can be set to NEGA(tive) or POSI(tive). At the moment they are both switched to NEGA.

B. There is a white pot ('B' in the picture) marked 'H-position'. I can turn it only a few milimeters to th left or right, and when I turn it I don't see anything changing on the monitor screen. What is it for?

C. There is another white pot ('C' in the picture) which on my chassis is set fixed with hot glue. What is it for?

D. I have a problem with the Horizontal width of the picture on the monitor screen, I mean it's to wide and I lose about 1 or 2 cm. of the image on the left side and right side of the screen. I can't get it more narrow without a lot of distortion. I tried to adjust it with the 'H-SUB POSI' pot on the breakout PCB, but without any luck. What can be the cause of this? (The Vertikal height is OK and can be adjusted fine).

Re: questions about Kortek chassis

Posted: October 11th, 2008, 11:35 am
by chubsta
ckong wrote:I have an old neo geo cab with a 19" monitor in it and with a Kortek KTN 20 chassis:


D. I have a problem with the Horizontal width of the picture on the monitor screen, I mean it's to wide and I lose about 1 or 2 cm. of the image on the left side and right side of the screen. I can't get it more narrow without a lot of distortion. I tried to adjust it with the 'H-SUB POSI' pot on the breakout PCB, but without any luck. What can be the cause of this? (The Vertikal height is OK and can be adjusted fine).
I had the exact same problem with my Kortek KT monitor in my Lordsvale MVS - no amount of adjusting would fix the width problem. in the end i contacted http://www.eurocoin.com" in North London and took it into them. One service and £39 later and all was fixed - the engineer said that there were a number of problems on the board. Might be worth giving them a call - for the price its well worth an overhaul of your monitor...

Re: questions about Kortek chassis

Posted: October 11th, 2008, 1:20 pm
by grantspain
A= sync polarity switches,switches between positive and negative of vertical and horizontal sync.for standard jamma you need negative horizontal

B=horizontal position preset,that should do something-it should move left and right,sounds like its a broken pot

C=looks like x-ray protection,do not touch this as it is factory sealed and a safety adjustment

D= width problems could be down to a leaky capacitor,bad solder joints,the width coil broken or if the chassis uses a transistor for the width then that could be leaky.
one other possibility is a faulty diode on the east/west correction circuit

For 39 quid i would send it for a service to eurocoin mate

Re: questions about Kortek chassis

Posted: October 11th, 2008, 1:45 pm
by ckong
Thank you both for the replies.

@Chubsta, are you sure the link is correct?

GBP 39 is not so much, allthough I reckon postage from and to The Netherlands will add up.

Re: questions about Kortek chassis

Posted: October 11th, 2008, 3:34 pm
by yosai
^ http://www.eurocoin.co.uk/"

...Unless you wanted some blank coins?

:D

Re: questions about Kortek chassis

Posted: October 11th, 2008, 4:45 pm
by chubsta
yep, http://www.eurocoin.co.uk" - sorry about that...

Re: questions about Kortek chassis

Posted: October 13th, 2008, 10:18 am
by ckong
Problem solved. I posted the same questions on byoac, and there I got the solution for my width problem.

See http://forum.arcadecontrols.com/index.p ... #msg897552

Re: questions about Kortek chassis

Posted: October 13th, 2008, 1:33 pm
by grantspain
i do not understand why you did not adjust the width coil in the first place
your post comes across as you have tried everything including the width coil

Re: questions about Kortek chassis

Posted: October 13th, 2008, 4:16 pm
by ckong
grantspain wrote:i do not understand why you did not adjust the width coil in the first place
your post comes across as you have tried everything including the width coil
Width Coil? What's that? Until yesterday I never heard of it and I never saw one. I always thought that all screen adjustments, with the exception of horinzoal/vertikal position and flip-screen, had to be done with the breakout pcb. Now I know better. :D

Re: questions about Kortek chassis

Posted: October 13th, 2008, 9:58 pm
by grantspain
actually you raise an important issue,sometimes i forget that some things that are obvious to me are not so for others.
i shall do something in the monitor repair guide to help with this area ;)